The difference in quality between brake cables is not all that obvious. Even expert mechanics have a difficult time judging good and bad cables and in the absence of knowledge, price always win. I can't say if those are good cables or bad cables but they are cheap.
Cables are made up of wound strands of high-tensile wire. If you cut a cross section and look at it through a magnifying glass, you'll see it as a daisy shape. This shape is not desirable since it is quite rough, especially on the brake where high tension is used and we all know that the difference between great brakes and poor brakes is a rough cable. Quality cable thus undergoes some other processes to make it smoother - it gets drawn through a die to flatten the daisy petals and create a smoother outer circumference. This adds cost but makes the cable a pleasure to use and gives it longevity since it doesn't saw through the inner radius of a bend in the housing. One step up from this would be a coating but here's a catch. Teflon is not suitable. It is too soft. Black coated cable is touted as smoother, which it is, for a while. After a bit of use the Teflon or PTFE is rubbed off and the sawdust gums up the housing instead of reducing friction.
So far the only coating that works is Shimano's polymer, which ironically coats the smoothed-out cable in a rough, lizard-skin series of microscopic ridges. This is very expensive.
Look for a cable that is at least stainless (never galvanized) and at least flattened. If you have Dura Ace stuff, treat yourself with the polymer cable.
Finally, never replace a cable without replacing the housing. Housing wears out on the inside radius and creates friction.
